This is fundamentally about DRM, isn't it? There is a working open source implementation already, but the HDMI cartel won't allow an open source implementation to have the encryption keys required to interface with the DRM in existing devices?
Source devices aren't required to output a DRM'ed signal though, are they? I think the DRM is only required on the receiver side. In that case a compliant source wouldn't need any keys, and besides, that wasn't a blocker for the previous HDMI versions which supported DRM too.
IIUC they're required to do a handshake involving encryption. Which is a form of DRM to enforce centralized control over the device ecosystem even if the subsequent video signals are not encrypted.
